Device for helping a vehicle to negotiate an obstacle

ABSTRACT

A device for helping a wheeled vehicle to negotiate an obstacle includes: a frame; a plate having two ends, a first end being movable between a high position and a low position in which the plate constitutes an access ramp; a flap constituting a front surface of the device when the plate is in the high position and provides ramp access when the plate is in the low position; and a drive assembly for driving the first end between the low position and the high position. The drive assembly includes an actuator and a carriage movable along a longitudinal axis. The device further includes a pair of side railings rigidly connected to the carriage, each having a control profile controlling the position of the plate, and a pair of resilient bars arranged between the flap and side railings.

FIELD OF THE INVENTION

The present invention relates to a device for helping a vehicle to pass over one or more steps or a threshold, in particular for persons with reduced mobility using a wheelchair or for persons moving a wheeled carriage for transporting objects.

BACKGROUND

It is common for a shop or business, or even a residential building entrance, to have a street access including one or more steps.

Such a threshold is generally about ten to twenty centimeters and constitutes an obstacle that is often impassable for a person with reduced mobility or for delivery carriages.

Of course, this problem does not only concern external accesses and such steps can also exist inside these spaces, especially in older buildings. Steps can also be found for access to terraces.

One solution to allow a wheeled vehicle or carriage to pass over such a step is to provide a ramp.

A major restriction relating to the installation of such a ramp is the absence of permanent encroachment on the public highway, pavement and/or roadway, passageway, etc.

Indeed, although essential for a person with reduced mobility, their general rate of use remains relatively low. It is therefore necessary to be able to clear the passageway completely when these ramps are not in use.

Extendable and retractable ramps provide a valuable service but suffer from complex mechanics. Such ramps require a significant free distance of deployment restricting possibilities of implementation. Pavement irregularities put stress on their structure.

FR 2947224 describes a telescopic tilting ramp.

Tilting ramps, between a horizontal position and an oblique position, occupy very small spaces, but have a complex ramp drive mechanism. In such a device, the drive assembly responsible for the pivoting of the ramp suffers from a complexity that generates a lack of stability and reliability for high mechanical loads and a possibility of blockade when the ramp is moved.

Such a device is described, for example, in FR 3044271, on behalf of the applicant.

A major concern of the applicant is to ensure stability and strength for high loads by its device while occupying very small spaces with simpler mechanisms.

SUMMARY

A device for helping a wheeled vehicle to pass over an obstacle, in particular for a person with reduced mobility, comprises a stationary frame comprising a bottom and two symmetrical parallel side walls. The help device comprises a plate provided with two ends, a first end being movable between a high position and a low position in which said plate constitutes an access ramp. The help device comprises a flap constituting a front face of the device in the high position of the plate and forming a second access ramp in the low position of the plate. The help device comprises a drive assembly for driving said first end between the low position and the high position, said first end being supported by said drive assembly at least in the high position. Said drive assembly comprises an actuator having a fixed end supported by the frame and an end movable between a retracted position and an extended position. Said drive assembly comprises a carriage translationally movable along a longitudinal axis, the movable carriage being translationally driven by said movable end of the actuator. Said drive assembly comprises a pair of side railings integral with said carriage and each having a control profile controlling the position of said plate. Said drive assembly includes a pair of resilient bars disposed between said flap and the ramps such that in the high position, the resilient bars exert traction on the flap in the closed position and in the low position the resilient bars press against the flap in the open position to constitute a ramp access rolling surface.

Thus, the invention proposes an easy, simple, robust and reliable drive assembly for a device for helping a vehicle to pass over an obstacle.

In one embodiment, the control profile has a central sloping portion so that a translation of the side railings along said longitudinal axis controls a movement of said plate between the low position and the high position. The control profile also has a substantially horizontal upper portion so that the bearing of the plate against the control profile generates a force substantially perpendicular to said longitudinal axis. The control profile is simple and reliable. The control profile reduces the possibility of the plate blocking by moving between the high position and the low position.

In one embodiment, the flap comprises an external wall in the high position and a lower wall in the low position for contacting a ground. The flap further comprises an internal wall in the high position and upper wall in the low position to provide a rolling surface, said walls being non-parallel to each other. The two-wall flap is more robust and can carry more load.

In one embodiment, the flap is hinged to the frame. The hinge with the frame is reliable.

In one embodiment, the resilient bars comprise gas springs. Power consumption, for example electrical power, is reduced. The gas springs are reliable and can adapt to the load supported by generating pressing or traction proportionate to the weight to be lifted.

In one embodiment, the resilient bars are arranged in the vicinity of said parallel side walls.

In one embodiment, the resilient bars are hinged to the flap and to the carriage. The arrangement of the resilient bars is reliable and reduces the overall space of the help device.

In one embodiment, the plate, in the low position, rests on the frame. In this way, the drive assembly and the resilient bars are at rest and free of stress.

In one embodiment, the plate comprises two wheels rollably mounted on the control profile. The wheel rolling operation on the control profile is reliable. Manufacturing costs are restricted.

In one embodiment, the bottom of the frame has a sloping portion remote from the flap and optionally a substantially horizontal portion close to the flap. Advantageously, an electronic control board is mounted to the sloping portion. The inclination facilitates discharge by gravity in the event of accidental liquid infiltration into the frame.

In one embodiment, the actuator has an axis of translation between the retracted position and the extended position intersecting with the longitudinal axis of the carriage. The fixed end of the actuator may be elevated. The depth of the device may be rearwardly reduced.

In one embodiment, the actuator is in the central position. The forces are thus evenly distributed between the two side railings having control profiles.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will be set out in detail in the following description, made with reference to the appended drawings, in which:

FIG. 1 is a perspective view of a device according to one embodiment, in a high position.

FIG. 2 is a perspective view of the device of [FIG. 1 ] free of the plate, in the high position.

FIG. 3 is a perspective view of the device of [FIG. 1 ], in a low position.

FIG. 4 is a perspective view of the device of [FIG. 1 ] free of the plate, in the low position.

FIG. 5 is a cross-sectional view in a vertical longitudinal plane of the device of [FIG. 1 ], in the high position.

FIG. 6 is a cross-sectional view in a longitudinal vertical plane of the device of FIG. 1 , in the low position.

FIG. 7 is a sectional view in a longitudinal vertical plane of the device of FIG. 1 , between the low position and the high position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The appended drawings contain, for the most part, elements of certainty. They may therefore not only serve to improve understanding of the present invention, but also contribute to its definition, where appropriate.

There is a need for a device 1 for helping to pass over a difference in altitude between two levels, a first level called the lower ground 3 and a second level called the upper ground 5. The difference in height is a step at the entrance to a room, a shop, an office or a height from the outside of any place. For example, people in wheelchairs or delivery people with carriages want access to such buildings. The step is arranged vertically between the lower ground 3 and the upper ground 5. In the rest state, the step extends from the upper ground 5 to the lower ground 3.

The help device 1 ensures installation of an access ramp with a slope of less than 20%, or even less than 15%, 10% or 5% depending on regulatory or environmental constraints. The help device 1 is to be inserted or embedded into the upper ground, starting from the step. A generally parallelepiped shaped reserve is made in the step and the upper ground.

The help device 1 comprises a frame 2 constituting an open box within which the ramp is housed. The ramp may have a lifting end, in which case the ramp is tiltable as illustrated in the drawings. The help device 1 has a height equal to or slightly less than the height of the step. The help device 1 has a length depending on the height of the step to avoid too steep a slope.

The frame 2 has dimensions adapted to the height of the step, width of the access and dimensions of the vehicle contemplated. For example, the box may have a height in the order of 6 to 20 centimeters allowing insertion into most grounds, such as a concrete, brick or other slab. An orthonormal reference frame with axes X, Y and Z is used. X is the longitudinal axis. Y is the transverse axis. Z is the vertical axis. The help device 1 comprises a plate 9. In the low position, the plate 9 constitutes the ramp set up by the help device 1. In the high position, the plate 9 constitutes a cover panel. The plate 9 is mounted in the frame 2. The frame 2 is installed in such a way that the plate 9 constitutes a surface flush with the upper ground of the premises in the high position. The plate 9 may be matched to the rest of the upper ground, for example by respecting the geometry, covering, decoration, etc.

The help device 1 comprises a front flap 11 constituting a front surface of the step. The flap 11 is generally vertical in the high or rest position of the help device 1. In the high position, the flap 11 closes a front side of the frame. The flap 11 has a generally rectangular shape. The flap 11 has a triangular transverse cross-sectional shape in a plane XZ.

The flap 11 comprises a first external wall 13 in the high position and a lower wall 13 in the low position for contacting the lower ground 3. The flap 11 further comprises a second wall 15. The second internal wall 15 is in the high position and upper in the low position to provide a rolling surface. Said walls are non-parallel to each other. The second wall 15 is inclined with respect to the first wall 13. The second wall 15 forms a rolling surface for access to the ramp. The rolling surface has a slope of less than 30%, or even less than 20%, 15% or 10%.

The second wall 15 is shorter than the length of the first wall 13 along the transverse axis Y. Thus, the second wall 15 can partially enter the frame 2 in the closed position. The first wall 13 closes a front side of the frame 2 in the high position. The first wall 13 comprises an outer side 17 which comes into contact with the ground in the low position and an internal face 19. The internal face 19 receives the second wall 15.

In the high position, the flap 11 comprises a free upper end. In the high position, the flap 11 comprises a hinged lower end. The edges of the two ends are parallel along the axis Y.

The two walls 13 and 15 are fitted together by folding and welding. Wall 13 is formed by a sheet metal part. Wall 15 is formed by a sheet metal part. The sheet metal of wall 13 is wider than the sheet metal of wall 15 along the axis Z in the closed position. The difference in width forms a foldover. The foldover of the wall 13 is folded onto the wall 15. The fold of the wall 13 constitutes the free end of the flap 11. The fold of the wall 13 has a shape free of sharp corners. At the free end of the flap 11, the fold of the wall 13 facilitates access to the ramp. Between both walls, a profiled U-shaped bar 14 is mounted substantially in the middle of the flap 11 to increase strength of the flap 11 to warping and strength to bending of the wall 15 during rolling. The bar 14 is parallel to the axis Y. The flap 11 carries a maximum load of 3500 N.

The flap 11 is hinged along a hinge axis extending along the axis Y.

In the high position, the upper end is formed by the fold of the wall 13. The upper end is flush with the upper surface of the plate 9. The upper end is disposed in front of the plate 9. From top to bottom, the wall 15 extends away from the wall 13 into the interior of the frame. A flange 16 constitutes the base of the triangular cross-section. The flange 16 is formed by bending the sheet metal of the wall 15. The flange 16 is joined to the wall 13, for example by welding and/or riveting. The flange 16 is parallel and close to the bottom of the frame 2. In the low position, the flange 16 is substantially vertical. The flange 16 faces the free end of the plate 9. The height of the flange 16 is close to and slightly less than the height of the upper surface of the plate 9. The upper surface of the plate 9 and the wall 15 are substantially coplanar.

The frame 2 is stationary in that it forms, after installation, an immovable structure of the help device 1 with respect to its installation environment such as the ground or the pavement. The frame 2 comprises a bottom 21, parallel side walls 23, 24 constituting the sides, a rear wall 25 and support elements for the plate 9. The term rear is used here in contrast to the front of the help device 1 intended to come into the vicinity of the lower ground 3, for example at the facade of the building. The term rear can also be seen as synonymous with internal in the case of a building. The rear wall 25 is perpendicular to the side walls 23, 24. The frame 2 can be made of stainless steel sheet. The front ends of the bottom 21 and the side walls 23, 24 define a mouth of the frame 2. During deployment, the flap 11 exits the frame 2 through the mouth. The mouth is closed by the flap 11 in the rest position.

In general, the bottom 21 is mounted in a housing provided for this purpose in the upper ground 5 of the room. At least one part of the bottom 21 is outwardly inclined, for example by about 15°. Optionally, another part is horizontal and substantially parallel to the plate 9 in the high position. The bottom 21 supports components of the help device 1. A control member 22 can be mounted to the inclined part of the bottom 21. Said control member 22 comprises an actuator 31. The inclination facilitates gravity discharge in the event of accidental liquid infiltration into the frame 2. In addition, the depth of the recess to be dug to house the help device 1 is reduced to the rear and the risk of interfering with a structural element of the building or a pipe is reduced. [0048] [FIG. 3 ] represents the help device 1 in the low position. The rear end or second end of the plate 9 remains at substantially the same height as the vertex of the rear wall 25. The front or first end of the plate 9 is lowered. The flap 11 is in the open position. The flap 11 projects from the frame 2. The flap 11 has a forwardly projecting upper end and a lower end adjacent to the front end of the plate 9.

The help device 1 comprises a pair of caps 27, 29 disposed parallel to the side walls 23, 24. The caps 27, 29 also constitute the sides. The distance between the cap 27, 29 and the corresponding side wall 23, 24 is about 30 mm. Twice this distance is approximately equal to the difference in the lengths of the two walls 13, 15 of the flap 11. The external wall 13 is longer than the length of the internal wall 15. In the high position, the internal wall 15 is partly between the caps 27, 29.

As illustrated in [FIG. 1 ], the caps 27, 29 have upper faces that are flush with the plate 9 in the high or rest position. The caps 27, 29 close the frame 2. The caps 27, 29 are not represented in FIGS. 2, 4, 5, 6 and 7 . The caps 27, 29 are mounted embedded within the frame 2 by means of screws and nuts.

The help device 1 comprises a drive assembly 30 visible in [FIG. 2 ] for example. The drive assembly 30 comprises an actuator 31, preferably an electric cylinder. An alternative with a mechanical cylinder manually operated, for example by a crank, is possible. The actuator 31 applies a force of at least 200 N along the longitudinal axis X to operate the help device. Here, the actuator 31 is unique.

The actuator 31 comprises a fixed end 32, directed rearwardly of the frame and supported by the inclined part of the bottom 21. A yoke may connect the fixed end 32 to the bottom 21. The actuator 31 comprises a movable end 33 opposite to the fixed end 32. The movable end 33 moves between a retracted position and an extended position along the bottom 21.

The drive assembly 30 further comprises a movable carriage 35 and a pair of side railings 36, 37. The carriage 35 is generally rectangular in shape. The length of the carriage 35 is oriented between the side walls 23, 24, parallel to the rear wall 25 along Y. The width of the carriage 35 is oriented parallel to the side walls 23, 24 along X.

The carriage 35 comprises a chassis made of cut and folded sheet metal. The chassis comprises a generally rectangular bottom and side edges. The chassis of the carriage is made of sheet steel with a thickness of between 1 and 4 mm, preferably 2 to 3.5 mm. The side edges are substantially vertical. The side edges are downwardly folded. The side edges form stiffeners.

The movable carriage 35 is translationally mounted along a longitudinal axis X parallel to the side walls 23, 24. The movable carriage 35 is translationally driven by the movable end 33 of the actuator 31. The movable end 33 is connected substantially to the middle of a rear end of the carriage 35. A yoke may connect the movable end 33 to the carriage 35.

The carriage 35 further comprises at its rear end, substantially in the middle, two parallel upwardly projecting plates, each having a bore and allowing the movable end 33 of the actuator 31 to be housed to provide the hinge between the carriage 35 and the actuator 31.

The pair of side railings 36, 37 are supported by the carriage 35. The side railings 36, 37 are housed in the caps 27, 29 in the low position. The side railings 36, 37 are housed underneath the plate 9 in the high position. Each side railing 36, 37 has a control profile controlling the position of the plate 9. Said control profile comprises a central portion 38 and an upper portion 39. The central portion 38 has a slope of approximately 10 to 45°. The choice of the slope depends on the size of the step to be negotiated. On the other hand, the upper portion 39 is substantially horizontal.

The horizontal portion 39 is at least 20 mm long.

During the translation of the side railings 36, 37 along the longitudinal axis X, the sloping central profile 38 controls movement of the plate 9 between the high position and the low position. The slope of the central profile 38 is generally less than 45°. A leverage between the actuator 31 and the plate 9 is present. The actuator 31 applies a small force over a long stroke. The side railings 36, 37 exert a high force on the plate 9 over a short stroke. Thus, the front end of the plate 9 is movable over a shorter stroke than the actuator 31 and undergoes a higher force than the force applied by the actuator 31. The actuator 31 is compact in height while its length is easy to accommodate.

The horizontal upper portion 39 allows a force perpendicular to the longitudinal axis X to be generated when the plate 9 bears against the control profile in the high position. The force applied by the plate 9 on the control profile is devoid of a horizontal component. The upper portion 39 provides stable position for the plate 9 in the high position.

The side railings 36, 37 are made of stainless steel sheet. A very small distance of about 10 mm between the side railing 36, 37 and the corresponding side wall 23, 24 provides a clearance to avoid friction and jamming of the side railing 36, 37.

The drive assembly 30 further comprises a pair of resilient bars 40, 41. Preferably the resilient bars 40, 41 comprise gas springs. The resilient bar 40, 41 is disposed between the flap 11 and the corresponding side railing 36, 37. The resilient bars 40, 41 are arranged in a plane XZ parallel to the longitudinal axis. The resilient bar 40, 41 is hingedly mounted, at one end, to the flap 11. A yoke may be attached to the wall 15 and support the resilient bar 40, 41. At an opposite end, the resilient bar 40, 41 is hingedly mounted to the corresponding side railing 36, 37 of the carriage 35. The resilient bar 40, 41 is hingedly mounted, at one end, to the internal face 19 of the first wall 13 of the flap 11.

The resilient bars 40, 41 are arranged parallel to the side walls 23, 24. The thickness of the side railings 36, 37 is approximately 10 mm. The large diameter of the resilient bars is about 12 mm. These dimensions are substantially smaller than the distance between the cap 27, 29 and the corresponding side wall 23, 24. The resilient bars 40, 41 are housed in the caps 27, 29 in the high position. In both the high and low positions, the resilient bars 40, 41 are inclined with respect to the horizontal. The inclination of the spring rods 40, 41 ensures proper lubrication of the gas spring rod. The inclination of each resilient bar 40, 41 also ensures a long service life of the gas spring.

In the low position or open position, the resilient bars 40, 41 press against the flap 11. A pressing force of approximately 40 N along the longitudinal axis directed from the rear to the front is desirable to maintain the flap 11 in the open position. The stroke of each resilient bar 40, 41 is approximately 30 mm.

The resilient bars 40, 41 apply an adaptable prestress to the ground. The resilient bars 40, 41 press the flap 11 to the ground. If, for example, there is a contingency, such as the presence of waste below the flap 11, the prestress of the resilient bars 40, 41 allows the flap 11 to crush some of the waste. The external wall 13 of the flap 11 is substantially horizontal. The user operates the ramp comfortably.

The carriage 35 rests on slides 43 mounted to the horizontal part of the bottom 21. The slides 43 are horizontal. The rails 43 are parallel. Here, the slides are two in number. Embodiments with three or more slides are provided. The slides 43 may be in the form of a metal profile with a smooth and hard upper sliding surface. The carriage 35 is provided with two shoes per slide. The shoes underneath the carriage 35 are not visible in the figures. The shoes may be made of a synthetic material with a low coefficient of friction, for example based on PTFE.

The frame 2 further comprises mechanical end stops 45. As illustrated in [FIG. 4 ], four mechanical stops 45 are disposed on the front part of the bottom 21. The mechanical stops 45 limit the stroke of the actuator 31. In addition, the control unit controls the current consumption in the case of an electric actuator.

The frame 2 further comprises pins 46 projecting from the bottom 21 towards the front end of the plate 9. In the low position, the front end of the plate 9 rests on the pins 46.

The hinging of the flap 11 to the frame 11 may be achieved with hinges 47. The hinges 47 are attached on the one hand to the lower end of the flap 11, and on the other hand, to a front end of the bottom 21. In this example, three hinges are used to make this hinging of the flap 11. Embodiments with one, two or four hinges are provided. These hinges 47 are mounted along the same axis of rotation along Y which is fixed and substantially horizontal and perpendicular to the longitudinal axis.

As represented in [FIG. 2 ], the hinging of the plate 9 to the frame 2 can be made as follows. The frame 2 comprises two pairs of vertical plates 49, 50. Each plate 49, 50 is in the form of a flat rectangular part, for example made of sheet metal. Each plate 49, 50 rests on the rear end of the inclined part of the base 21 with a small lower side. Each plate 49, 50 is arranged next to the rear wall 25. The plates 49, 50 may be welded to the bottom 21. An upper side of the plates 49, 50 has a semicircular recess. The frame 2 comprises a pivot pin segment 51 for each pair of plates 49, 50. Each end of a pivot pin segment 51 projects into the semicircular recess of a plate. Each pivot pin segment 51 can be held in the semicircular recesses by circlips, retainer rings or internally toothed washers. Each pivot pin segment 51 is supported by a pair of plates. The pivot pin segments 51 are adjacent to the upper end of the rear wall 25. The pivot pin segments 51 are spaced apart to ensure proper stability. The plate 9 rests on the pivot pin segments 51. The plate 9 can be secured to the pivot pin segments 51 by means of flanges. The plate 9 is pivotably mounted relative to the frame 2. Pivoting is carried out over a limited angle, for example less than 15°, so that the distance between the rear end of the plate 9 and the rear wall 25 remains negligible, for example less than 3 mm.

Driving the plate 9 by the drive assembly 30 may be made as follows. The plate 9 comprises two rectangular parts which downwardly project from the lower face of the plate 9 adjacent the side walls 23, 24. Each rectangular part comprises a journal which projects inwardly of the frame 2. A wheel 53 with a substantially horizontal axis is rotatably mounted to each journal. The wheel 53 rolls on the control profile of the corresponding side railing 36, 37. The thickness of the rectangular part is very small, typically about 10 mm. The rectangular part is partly housed between the side railing 36, 37 and the corresponding side wall 23, 24.

In the high position of the plate 9, each wheel 53 is located on a front end of the upper horizontal portion 39 of the control profile. The horizontal upper portion 39 generates a force perpendicular to the longitudinal axis X when the plate 9 bears against the control profile in the high position. The drive assembly 30 is withdrawn in the high position. Said upper portion 39 of the control profile desynchronizes the movement of said plate 9 with respect to the movement of the flap 11.

When the drive assembly 30 is actuated to operate the help device 1, the carriage 35 slides forwardly along the slides 43, the side railings 36, 37 move forwardly, the wheels 53 roll along the upper horizontal portion 39 and the central sloping profile 38 of the control profile. The upper portion 39 of the control profile allows the wheels 53 to roll horizontally. The plate 9 remains in the high position along the upper portion 39. The resilient bars push the flap 11. The flap 11 starts to open with the wheels 53 on the upper portion 39 of the control profile. And then, the wheels 53 roll down the central portions 38 of the control profile. The plate 9 starts to rotate about its hinge axis. The resilient bars 40, 41 push the flap 11. And then, the wheels 53 leave the control profiles. The front end of the plate 9 rests on the pins 46 of the frame 2. The plate 9 is in the low position. The flap 11 comes into contact with the ground. The resilient bars 40, 41 come to be pre-stressed. The carriage 35 reaches the end stop 45.

To close the flap 11 of the help device 1, the drive assembly 30 is actuated in the opposite direction. The carriage 35 slides backwardly along the slides 43. The resilient bars 40, 41 are expanded. The side railings 36, 37 move backwardly. And then, the wheels 53 come into contact with the corresponding side railings 36, 37. And then, the wheels 53 roll along the central sloping portions 38. The plate 9 starts to rotate about its axis. The plate 9 starts to rotate upwardly while the flap 11 is stationary. The resilient bars 40, 41 continue to exert traction on the flap 11. And then, the resilient bars 40, 41 pull the flap 11. The flap 11 moves away from the lower ground. The flap 11 continues to close, with the wheels 53 on the central portions 38 of the control profiles. The plate reaches the high position at the end of the central portion 38 of the control profile. The wheels 53 roll horizontally on the horizontal portion 39 of the control profile. The plate 9 remains in the high position along the path of the upper portions 39 by the wheels 53. The plate 9 is stationary while the flap 11 continues to pivot to its closed position. The resilient bars 40, 41 apply a traction force to the flap 11. The flap 11 reaches a vertical position. The carriage 35 reaches the end stop 45. The flap 11 closes the frame 2. The wheels 53 are supported by the upper portion 39 of the control profile. The plate 9 rests on the side railings 36, 37, the actuator 31 being withdrawn due to the absence of force with axis X onto the side railings 36, 37.

Thus, the flap 11 follows the movement of the carriage 35 within the elasticity of the resilient bars 40, 41. The plate 9 is movably driven only over a central part of the travel of the carriage 35. In order to press the flap 11 to the ground, in the absence of movement of the plate 9, the force of the actuator is devoted to said flap. Three states corresponding to the three phases can be distinguished. In a first, high state, the plate 9 is stationary, the carriage 35 and the flap 11 are moving. The flap 11 comes out of its housing and moves away from the front end of the plate 9. In a second state, the plate 9, the carriage 35 and the flap 11 are moving. In a third, low state, the flap 11 is stationary, the carriage 35 and the plate 9 are moving. The flap 11 is in contact with the low ground. If the low ground is lower than the bottom of the frame, the third phase is reduced, with the flap movement stopping shortly before the plate 9 stops.

In other words, the device for helping to pass over an obstacle by a wheeled vehicle, in particular for a person with reduced mobility, comprises a stationary frame, a plate comprising a first end movable between a high position and a low position, said plate constituting an access ramp, and a second end which is hinged to the frame, a flap constituting a front face in the high position and constituting access to the ramp in the low position of the plate, the flap and the ramp forming a rolling surface, and a drive mechanism for driving the plate between the low position and the high position, said first end of the plate being supported by said drive mechanism at least in the high position The drive mechanism comprises an actuator comprising a fixed end supported by the frame and an end movable between a retracted position and an extended position, a carriage translationally movable along a longitudinal axis, translationally driven by said movable end of the actuator, a pair of side railings integral with said carriage and each having a control profile controlling the position of said plate, and a pair of bars disposed between said flap and the side railings, in the high position exerting traction on the flap and in the low position pressing against the open flap to constitute a rolling surface for access to the ramp. In the low position, the drive mechanism is withdrawn from the weight of the plate. In the high position, the side railings, carriage and actuator are withdrawn from the weight of the plate. 

1. A device (1) for helping a wheeled vehicle to pass over an obstacle, the device comprising: a stationary frame (2) comprising a bottom (21) and two symmetrical parallel side walls (23, 24), a plate (9) provided with two ends, a first end being movable between a high position and a low position in which said plate (9) constitutes an access ramp, and a flap (11) constituting a front face of the device (1) in the high position of the plate (9) and constituting access to the ramp in the low position of the plate (9), and a drive assembly (30) for driving said first end between the low position and the high position, said first end being supported by said drive assembly at least in the high position, said drive assembly (30) comprising: an actuator (31) provided with a fixed end (32) supported by the frame (2) and an end movable between a retracted position and an extended position, and a carriage (35) translationally movable along a longitudinal axis, the movable carriage (35) being translationally driven by said movable end (33) of the actuator, a pair of side railings (36, 37) integral with said carriage (35) and each having a control profile controlling the position of said plate (9), and a pair of resilient bars (40, 41) disposed between said flap (11) and the side railings (36, 37) so that in the high position, the resilient bars (40, 41) exert traction on the flap (11) in the closed position and in the low position, the resilient bars (40, 41) press against the flap (11) in the open position to constitute a rolling surface for access to the ramp.
 2. The device according to claim 1, wherein the control profile has a central portion (38) sloping so that a translation of the side railings (36, 37) along said longitudinal axis controls a movement of said plate (9) between the low position and the high position, and a substantially horizontal upper portion (39) so that the bearing of the plate (9) against the control profile generates a force substantially perpendicular to said longitudinal axis.
 3. The device according to claim 1, wherein the flap (11) comprises an external wall (13) in the high position, which contacts a ground surface when lowered to a low position (15) in the high position, said internal wall (15), when in the low position, provides a rolling surface, said walls being non-parallel to each other.
 4. The device according to claim 1, wherein said resilient bars (40, 41) comprise gas springs, and are arranged proximate to said side walls (23, 24) and hinged between the flap (11) and the carriage (35).
 5. The device according to one claim 1, wherein the plate (9), in the low position, rests on the frame (2).
 6. The device according to claim 1, wherein the plate (9), in the high position, rests on said side railings (36, 37).
 7. The device according to claim 2, wherein said upper portion (39) of the control profile desynchronizes the movement of said plate (9) with respect to movement of the flap (11).
 8. The device according to claim 1, wherein the plate (9) comprises two wheels (53) rollably mounted to the control profile.
 9. The device according to claim 1, wherein the bottom (21) of the frame (2) has a sloping portion remote from the flap (11), an electronic control board (22) being mounted to the sloping portion.
 10. The device according to claim 1, wherein the actuator (31) has an axis of translation between the retracted position and the extended position intersecting with the longitudinal axis of the carriage (35).
 11. The device according to claim 1, wherein the bottom (21) of the frame (2) has a sloping portion remote from the flap (11) and a substantially horizontal portion proximate to the flap (11), an electronic control board (22) being mounted to the sloping portion. 